Skin is home to a variety of normal microbiota, but forms a barrier that microbes have to penetrate in order to set up an infection.
Correct Answer: It is a barrier to invading organisms
Bacteria can enter the skin via hair follicles.
Correct Answer: The hair follicles
Necrotizing fasciitis is a serious bacterial infection usually caused by group A streptococci acting either alone or in combination with other bacteria through a synergistic effect.
Correct Answer: Group A Streptococcus
Inflammatory acne is caused by the bacterium Propionibacterium acnes, which is the predominant anaerobe of the skin and part of the normal microbiota.
Correct Answer: Propionibacterium
Scalded skin syndrome is caused by an exotoxin produced by Staphylococcus aureus.
Correct Answer: Staphylococcus aureus exotoxin
Gas gangrene is caused by Clostridium perfringens, which produces toxins, proteinase, lipase, hyaluronidase, and collagenase, all of which destroy tissue.
Correct Answer: Clostridium perfringens
Smallpox produces an abrupt onset of fever, chills and muscle aches. A rash appears 3–4 days later and evolves to papulovesicles, which are seen most prominently on the head and extremities and become pustular over 10–12 days.
Correct Answer: Papulovesicular rash on the head and extremities
Chickenpox is caused by the varicella-zoster virus.
Correct Answer: Varicella-zoster
There are two forms of Herpes simplex virus. Herpes simplex type 1 infections are referred to as above-the-waist infections and produce lesions around the mouth referred to as cold sores. HSV-2 causes genital herpes.
Correct Answer: Herpes simplex type 1
Thrush is caused by Candida albicans and is the development of a whitish over-growth in the oral cavity.
Correct Answer: Candida albicans
The lesions associated with cutaneous leishmaniasis appear on the extremities or the face weeks to months after the bite of the sand fly.
Correct Answer: The bite of the sand fly
Conjunctivitis is inflammation of the inner membranes of the eyelids with an associated discharge. The infection is easily spread if a contaminated hand rubs the eyes.
Correct Answer: Infection of the eye
Neonatal gonorrheal ophthalmia is an infection seen in newborn infants delivered from mothers infected with Neisseria gonorrhoeae. In the past, this was treated with silver nitrate. However, it has been shown that today most mothers infected with Neisseria are also co-infected with Chlamydia which is not inhibited by silver nitrate. Therefore, the standard treatment for these newborns is with antibiotics.
Correct Answer: Antibiotics
A wide variety of organisms cause most skin infections.
Correct Answer: Incorrect
Folliculitis causes boils, which are largely impervious to antibiotics, and is treated by draining the boils (abscesses).
It is true that gas gangrene causes necrosis of tissues and can be rapidly fatal.
Correct Answer: Correct
Cutaneous anthrax is usually a mild infection. Inhalation anthrax is usually fatal.
Correct Answer: Incorrect
The eye is an immunologically protected site and protected from infection by the mechanical and chemical action of tears, which are produced by the lachrymal apparatus.